Process of dissociating acetylene.



J. M. MOREHEAD.

PROCESS OF DISSOGIATING ACETYLENE.

APPLICATION rum) 1 211.3, 1908.

986,489; Patented Mar. 14, 1911.

. I Wneba ea: ELI/@7650)? UNITED STATESEA'IENT OFFICE.

JOHN M. MOBEKEAD', OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION CARBIDE COMPANY,

OF CHICAGO, ILLINOIS, L CORPORATION OF VIRGINIA.

PROCESS Oi DISSOCIA'IING ACETYLENE.

ful Improvements 'in Processes of Dissociating Acetylene, of which thefollowing isa. specificationf I In the ordinary process of producing la-mpblack .from gas, oil or other carbonaceous fuel, ,the fuel is ignited and burned with a deficit ofoxygen. The flame. produced by such incomplete combustion is-impinged upon some cold surface, whereon the carbon deposits and 1s scraped oil from time to time. This process 15 very wasteful, as a large proportion of the carbon contained in the fuel is burned and lost, while a very considerable portion of the-combined carbon is not deposited on the cold surface but escapes with the outgoing gases. Lampblack may be produced from acetylene by this method of incomplete combustion, but the cfiiciency of the process is so low that-it is not commercially practicable.

It is possible to produce lampblack from acetylene by dissociating the compressed gas, as described in my U. S. Letters Patent No.' 779,798, granted January 10,1905. The

gas, subjected to a ressure in excess of from one to two atmosp, leres, is exploded, whereupon instant dissociation takes place, the carbon, composing approximately ninetytwo per cent. of acetylene, being deposited 1n the retainer as a solid, while the hydrogen remains as a gas. This process, while e'ffi-.

cicnt, is expensive and at the same time attended with more or less danger, as at the instant of dissociation excessive pressures are generated in the"container.

My present invention is a process of dissociating acetylene by heat, at approximately atmospheric pressure. Y

i If acetylene is subjected to su ratmosphcric temperatures, chemical an physical changeaof great complexity take place. At

538 F., some of the acetylene condenses to.

benzene. As the temperature is further increased, ethylene, methane, styrolene, naphthalene and other decomposition and polymerization products result, either successively or simultaneousl Y or smaller proportion of pure hydrogen and carbon, due to complete dissociation of a portion of the gas. here are also produced along with a larger in t ing 17, cosed by a' plate which receives 1 p 4 Specification ot lctter ratent. Patented Blur. 14,1911.

Application filed February 8,.1908. Serial No. 414,014.

a number of liquid or semi-liquid hydrocarbons resembling ta}, If these olymers of acetylene are continuously sub ected to a tem erature at or in excess of that which ro uced 'then1,,.they break down and bake into a sort of dense hard gray coke, quite unlike lampblack.- This hard coke gr idually fills up the -receptacle'in which it is produced and eventually interrupts the process.

I have found that acetylene-at practically atmospheric pressures, if suddenly heated to a temperature at or in excess of that corresponding to a dull red heat; dissociates instantly and quietly ihto its elements of carbonand hydrogen without the production of any of its polymers, and that the carbon so produced is either deposited in. the heatingretort, or is carried along with the aseous hydrogen as a light fioccl en powder,-

easily handled and practically chemically ure. My present process of inakin lamplack from acetylene is based on t iis discovery.

Suitable apparatus for carrying out the recess is shown in the accompanying drawmg, in which: a

Figure 1 is a side elevation, pa'rtly in axialv section; and Fig. 2 is a transverse ver tical section of the lampblack-receivin and settling chamber, on the line II-fI of Fig.1.

"he specific apparatus illustrated comhustlc-pipcs 4. A lateral outlet 5 for prod acts of combustion opens from the upper end of the chamber 1 into a waste-flue 6.

Axially supported within the heat-in chamber 1 is a retort 7, which may be of rebrick or castiron. The upper end 8 of this retort is seated in the roof of the. chamber and its lower end 9 rests in the socket 10 of a flue-piece 11. An acetylene dischargepipe 12 opens centrally into the upperbend' y of the retort 7, being fed with gas pipe 13. Around this pipe 12 1s a 3acket 14 through which water is c rculated by sup ly and discharge pipes 15 .16. Seated.

be up r end 8 of the retoi't is a bush- Q seams blast-noziles 18, fed by a pi e 19. The fluepiece 11 which supports t e lower end of the 'retorts opens laterally through a short flue 'into a chamber 21 for receiving and settlin the lampblack ,from the retort. This 0 amber, which may consist of sheetiron, has downwardly conver in sides 22 and a horizontal top 23. In t eiwttom of the chamber is a screw-conveyer 24 for delivcring the lampblack at one end. A pipe 25 for the residual hydro en leads from t e end of the settlin 26, having a vertical outlet pipe 27. T is pipe is connected, by a T-coupling 28, both to a pipe 29, having a valve'30, which serves to deliver the gas to the burners 3, and to a Waste-flue 31 having a valve 32. In using this apparatus to carry out the process, the retort 7 is heated, referably by gas introduced through the urners 3, to'or above the temperature of dullredness. A stream of acetylene, maintained at a temperature below its dissociation point by the water flowing through the jacket 14, is then delivered through pipe 12 into the upper end of the retort. The acetylene, issuing into the retort and suddenly heated to or all vc the temperature of dull redness, instantly and quietly dissociates the carbon being setfree in the form 0 lampblack,

which largely collects in the retort, while the free hydrogen passes'on through the settling chamber 21 and may be returned to the burners 3 toheat the retort.

The current of hydrogen may also carry some of the lampblack. into the settling chamber. As the retort becomes filled with lampblack,

chain er into a sealot the stream of acetylene iscut ofl', valve in hydrogen pipe 29 is closed and valve 32 in waste-pipe 31 is opened. An inert gas, preferably at the tem Jerature of the retort, or example hot r0 nets of combustion, is then forced into t e upper end of the retort throu h the nozzles 18, blowing the light lampb ack out of the retort and into the chamber 21, where it settles, to be removed acetylene into a chamber heated to at least the temperature of dull redness.

3. The process of dissociating acetylene, which consists in delivering a stream of acetylene, maintained at a temperature below its dissociation point, into a chamber heated to at least the temperature of dull redness.

In testimony whereof, I afiix my signature in presence of two witnesses.

J QHN M. MQREHEAD.

Witnesses:

E. F. PM, JOHN S. ADAMS. 

